1
|
Lee H, Friedman B, Lee K. Adaptive microwave impedance memory effect in a ferromagnetic insulator. Nat Commun 2016; 7:13737. [PMID: 27966536 PMCID: PMC5477504 DOI: 10.1038/ncomms13737] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 10/31/2016] [Indexed: 11/13/2022] Open
Abstract
Adaptive electronics, which are often referred to as memristive systems as they often rely on a memristor (memory resistor), are an emerging technology inspired by adaptive biological systems. Dissipative systems may provide a proper platform to implement an adaptive system due to its inherent adaptive property that parameters describing the system are optimized to maximize the entropy production for a given environment. Here, we report that a non-volatile and reversible adaptive microwave impedance memory device can be realized through the adaptive property of the dissipative structure of the driven ferromagnetic system. Like the memristive device, the microwave impedance of the device is modulated as a function of excitation microwave passing through the device. This kind of new device may not only helpful to implement adaptive information processing technologies, but also may be useful to investigate and understand the underlying mechanism of spontaneous formation of complex and ordered structures.
Dissipative systems may provide another platform towards adaptive electronics beyond adaptive biological systems. Here, Lee et al. report a non-volatile memristive microwave device based on adaptive tuning of the dissipative magnetic domains of a driven ferromagnetic system.
Collapse
Affiliation(s)
- Hanju Lee
- Department of Physics and Basic Science Institute for Cell Damage Control, Sogang University, Seoul 121-742, Korea
| | - Barry Friedman
- Department of Physics, Sam Houston State University, Huntsville, Texas 77341, USA
| | - Kiejin Lee
- Department of Physics and Basic Science Institute for Cell Damage Control, Sogang University, Seoul 121-742, Korea
| |
Collapse
|
2
|
Barrett N, Gottlob DM, Mathieu C, Lubin C, Passicousset J, Renault O, Martinez E. Operando x-ray photoelectron emission microscopy for studying forward and reverse biased silicon p-n junctions. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:053703. [PMID: 27250431 DOI: 10.1063/1.4948597] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Significant progress in the understanding of surfaces and interfaces of materials for new technologies requires operando studies, i.e., measurement of chemical, electronic, and magnetic properties under external stimulus (such as mechanical strain, optical illumination, or electric fields) applied in situ in order to approach real operating conditions. Electron microscopy attracts much interest, thanks to its ability to determine semiconductor doping at various scales in devices. Spectroscopic photoelectron emission microscopy (PEEM) is particularly powerful since it combines high spatial and energy resolution, allowing a comprehensive analysis of local work function, chemistry, and electronic structure using secondary, core level, and valence band electrons, respectively. Here we present the first operando spectroscopic PEEM study of a planar Si p-n junction under forward and reverse bias. The method can be used to characterize a vast range of materials at near device scales such as resistive oxides, conducting bridge memories and domain wall arrays in ferroelectrics photovoltaic devices.
Collapse
Affiliation(s)
- N Barrett
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - D M Gottlob
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - C Mathieu
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - C Lubin
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - J Passicousset
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif-sur-Yvette Cedex, France
| | - O Renault
- University Grenoble-Alpes, 38000 Grenoble, France and CEA, LETI, MINATEC Campus, 38054 Grenoble, France
| | - E Martinez
- University Grenoble-Alpes, 38000 Grenoble, France and CEA, LETI, MINATEC Campus, 38054 Grenoble, France
| |
Collapse
|
3
|
Nickel F, Gottlob D, Krug I, Doganay H, Cramm S, Kaiser A, Lin G, Makarov D, Schmidt O, Schneider C. Time-resolved magnetic imaging in an aberration-corrected, energy-filtered photoemission electron microscope. Ultramicroscopy 2013; 130:54-62. [DOI: 10.1016/j.ultramic.2013.03.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 03/06/2013] [Accepted: 03/08/2013] [Indexed: 11/16/2022]
|
4
|
Nepijko SA, Krasyuk A, Oelsner A, Schneider CM, Schönhense G. Quantitative measurements of magnetic stray field dynamics of Permalloy particles in a photoemission electron microscopy. J Microsc 2010; 242:216-20. [PMID: 21155993 DOI: 10.1111/j.1365-2818.2010.03472.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
By example of a Permalloy particle (40 × 40 μm(2) size, 30 nm thickness) we demonstrate a procedure to quantitatively investigate the dynamics of magnetic stray fields during ultrafast magnetization reversal. The measurements have been performed in a time-resolving photoemission electron microscope using the X-ray magnetic circular dichroism. In the particle under investigation, we have observed a flux-closure-dominated magnetic ground structure, minimizing the magnetic stray field outside the sample. A fast magnetic field pulse introduced changes in the micromagnetic structure accompanied with an incomplete flux closure. As a result, stray fields arise along the edges of domains, which cause a change of contrast and an image deformation of the particles geometry (curvature of its edge). The magnetic stray fields are calculated from a deformation of the X-ray magnetic circular dichroism (XMCD) images taken after the magnetic field pulse in a 1 ns interval. These measurements reveal a decrease of magnetic stray fields with time. An estimate of the lower limit of the domain wall velocity yields about 2 × 10(3) m s(-1).
Collapse
Affiliation(s)
- S A Nepijko
- Institute of Physics, University of Mainz, Mainz, Germany.
| | | | | | | | | |
Collapse
|
5
|
Mikkelsen A, Schwenke J, Fordell T, Luo G, Klünder K, Hilner E, Anttu N, Zakharov AA, Lundgren E, Mauritsson J, Andersen JN, Xu HQ, L'Huillier A. Photoemission electron microscopy using extreme ultraviolet attosecond pulse trains. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2009; 80:123703. [PMID: 20059146 DOI: 10.1063/1.3263759] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We report the first experiments carried out on a new imaging setup, which combines the high spatial resolution of a photoemission electron microscope (PEEM) with the temporal resolution of extreme ultraviolet (XUV) attosecond pulse trains. The very short pulses were provided by high-harmonic generation and used to illuminate lithographic structures and Au nanoparticles, which, in turn, were imaged with a PEEM resolving features below 300 nm. We argue that the spatial resolution is limited by the lack of electron energy filtering in this particular demonstration experiment. Problems with extensive space charge effects, which can occur due to the low probe pulse repetition rate and extremely short duration, are solved by reducing peak intensity while maintaining a sufficient average intensity to allow imaging. Finally, a powerful femtosecond infrared (IR) beam was combined with the XUV beam in a pump-probe setup where delays could be varied from subfemtoseconds to picoseconds. The IR pump beam could induce multiphoton electron emission in resonant features on the surface. The interaction between the electrons emitted by the pump and probe pulses could be observed.
Collapse
Affiliation(s)
- A Mikkelsen
- Department of Physics, Lund University, Box 118, 22100 Lund, Sweden
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Kaiser A, Wiemann C, Cramm S, Schneider CM. Influence of magnetocrystalline anisotropy on the magnetization dynamics of magnetic microstructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:314008. [PMID: 21828569 DOI: 10.1088/0953-8984/21/31/314008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The study of magnetodynamics using stroboscopic time-resolved x-ray photoemission electron microscopy (TR-XPEEM) involves an intrinsic timescale provided by the pulse structure of the synchrotron radiation. In the usual multi-bunch operation mode, the time span between two subsequent light pulses is too short to allow a relaxation of the system into the ground state before the next pump-probe cycle starts. Using a deflection gating mechanism described in this paper we are able to pick the photoemission signal resulting from selected light pulses. Thus, PEEM measurements can be carried out in a flexible timing scheme with longer delays between two light pulses. Using this technique, the magnetodynamics of both Permalloy and iron structures have been investigated. The differences in the dynamic response on a short magnetic field pulse are discussed with respect to the magnetocrystalline anisotropy.
Collapse
Affiliation(s)
- A Kaiser
- Forschungszentrum Jülich, Institut für Festkörperforschung IFF-9, and JARA-FIT, 52425 Jülich, Germany
| | | | | | | |
Collapse
|
7
|
Fukumoto K, Matsushita T, Osawa H, Nakamura T, Muro T, Arai K, Kimura T, Otani Y, Kinoshita T. Construction and development of a time-resolved x-ray magnetic circular dichroism-photoelectron emission microscopy system using femtosecond laser pulses at BL25SU SPring-8. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2008; 79:063903. [PMID: 18601413 DOI: 10.1063/1.2937648] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A femtosecond pulsed laser system has been installed at the BL25SU soft x-ray beamline at SPring-8 for time-resolved pump-probe experiments with synchronization of the laser pulses to the circularly polarized x-ray pulses. There are four different apparatuses situated at the beamline; for photoemission spectroscopy, two-dimensional display photoelectron diffraction, x-ray magnetic circular dichroism (XMCD) with electromagnetic coils, and photoelectron emission microscopy (PEEM). All four can be used for time-resolved experiments, and preliminary investigations have been carried out using the PEEM apparatus to observe magnetization dynamics in combination with XMCD. In this article, we describe the details of the stroboscopic pump-probe XMCD-PEEM experiment, and present preliminary data. The repetition rate of the laser pulses is set using a pulse selector to match the single bunches of SPring-8's hybrid filling pattern, which consists of several single bunches and a continuous bunch train. Electrons ejected during the bunch train, which do not provide time-resolved signal, are eliminated by periodically reducing the channel plate voltage using a custom-built power supply. The pulsed laser is used to create 300 ps long magnetic field pulses, which cause magnetic excitations in micron-sized magnetic elements which contain magnetic vortex structures. The observed frequency of the motion is consistent with previously reported observations and simulations.
Collapse
|
8
|
Woltersdorf G, Back CH. Microwave assisted switching of single domain Ni80Fe20 elements. PHYSICAL REVIEW LETTERS 2007; 99:227207. [PMID: 18233324 DOI: 10.1103/physrevlett.99.227207] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Indexed: 05/25/2023]
Abstract
We study the switching behavior of thin single domain magnetic elements in the presence of microwave excitation. The application of a microwave field strongly reduces the coercivity of the elements. We show that this effect is most profound at the ferromagnetic resonance frequency of the elements. Observations using time-resolved magneto-optic Kerr microscopy in combination with pulsed microwave excitation further support that the microwave assisted switching process is indeed based on the coherent motion of the magnetization.
Collapse
Affiliation(s)
- Georg Woltersdorf
- Universität Regensburg, Universitätsstrasse 31, 93040 Regensburg, Germany
| | | |
Collapse
|
9
|
Schönhense G, Elmers H, Nepijko S, Schneider C. Time-Resolved Photoemission Electron Microscopy. ADVANCES IN IMAGING AND ELECTRON PHYSICS 2006. [DOI: 10.1016/s1076-5670(05)42003-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
10
|
Schönhense G, Elmers HJ. PEEM with high time resolution—imaging of transient processes and novel concepts of chromatic and spherical aberration correction. SURF INTERFACE ANAL 2006. [DOI: 10.1002/sia.2433] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|